Stirring apparatus

ABSTRACT

In a stirring apparatus the slide ring packing for the stirring shaft extending into a high pressure vessel is disposed in the agitator gear housing about the drive shaft secured to the end of said stirring shaft in axial alignment therewith. For replacing the slide ring packing, said drive shaft may be disconnected from said stirring shaft and axially displaced with said slide ring packing through said gear housing into a tubular casing disposed thereabove and communicating therewith. The tubular casing is provided with a lateral opening through which the slide ring packing, now aligned therewith, may be replaced.

United States Patent 3,253,300 5/1966 Goveetal.

3,443,794 5/1969 Peterson Primary Examiner-Jordan Franklin Assistant Examiner--George V. Larkin Attorney-Edwin E. Greigg 259/ lO7X ABSTRACT: In a stirring apparatus the slide ring packing for the stirring shaft extending into a high pressure vessel is disposed in the agitator gear housing about the drive shaft secured to the end of said stirring shaft in axial alignment therewith. For replacing the slide ring packing, said drive shaft may be disconnected from said stirring shaft and axially displaced with said slide ring packing through said gear housing into a tubular casing disposed thereabove and communicating therewith. The tubular casing is provided with a lateral opening through which the slide ring packing, now aligned therewith, may be replaced.

srnmmc APPARATUS BACKGROUND OF THE INVENTION This invention relates to a stirring or agitating apparatus having a stirring shaft which extends sealed into a container, particularly a high pressure vessel. The shaft seal associated with agitators of this type is usually a slide ring packing.

l-leretofore, the gear housing of such stirring apparatus has been supported above the vessel by means of a particular framework ensuring a sufficient distance between the vessel and the housing to enclose a clutch between the upper end of the stirring shaft and the lower end of an output or drive shaft extending from the gear box and to permit after opening the clutch replacement of the stirring shaft seal. Thus, such a replacement was performed below the gear housing in the space provided by the framework between the vessel and the gear housing.

OBJECT, SUMMARY AND ADVANTAGES OF THE INVENTION It is an object of the invention to' provide an improved stirring apparatus in which the aforenoted framework and thus the space between the gear housing and the vessel is eliminated and a robust, compact and small weight agitator drive unit is provided which may be attached as a unit to a stirring tank, such as a high pressurevessel.

Briefly stated, according to the invention, the agitator drive and the stirring shaft seal, by arranging the latter in the gear housing, constitute a structural unit. Further, the stirring shaft is disconnectably coupled in the range of the stirring shaft seal with an output or drive shaft carrying said seal and constituting the continuation of the stirring shaft. Further, the seal disposed on the output shaft is axially displaceable in a direction away from the vessel,through the gear housing into a tubular casing which is mounted on the gear housing and provided with an access window. With the seal there are axially displaced the driving parts arranged at that side of the seal which is remote from the vessel.

Because of its low center of gravity, the agitator drive unit designed in the afore-outlined manner is of greater stability than previously known structures provided with a framework. Together with the framework and the separate housing that has been necessary for the stirring shaft seal (usually a slide ring packing), the fitting means provided heretofore between the different components of the structure may also be omitted. By disposing the stirring shaft seal within the gear housing, the slide rings of the seal and the bearings of the stirring shaft and of the output shaft may be disposed in a gear housing arrangement in an exact position with respect to one another, and, inasmuch as they are arranged in axial alignment, a flush rela tion therebetween may be ensured in a simpler manner than in known arrangements divided into several, subsequently fitted structural units. According to the invention, the replacement of the agitator shaft seal is no longer performed in a space between the gear housing and the vessel: the parts to be replaced are moved through the gear housing in an axial direction upwardly, in case of a vertical arrangement and taken out of the gear housing from that side thereof which is remote from the vessel. The structure is therefore designed in such a manner that the drive parts disposed in front of the parts to be exchanged (when viewed in the direction of said axial displacement), may be moved therewith outwardly through the gear housing. 1

The invention will be better understood and further objects and advantages will become more apparent from the ensuing detailed specification of a preferred, although exemplary, embodiment taken in conjunction with the drawing.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE EMBODIMENT Turning now to FIG. I, the agitator forming a structural unit is secured to a wall of a high pressure vessel (not shown) by means of a base plate 27. An agitator or stirring shaft I0 extends into the vessel and carries at its lower end the agitator elements, not shown, The opening in the base plate 27 through which the stirring shaft 10 extends, is hermetically separated from the inside of the vessel by means of a slide ring packing, details of which will be described hereinafter. The upper terminus of the stirring shaft 10 is formed by a tapered portion 32.

To the base plate 27 there is fixedly secured a housing 28 containing the slide ring'packing and the agitator drive. The lower part of housing 28' forms a chamber 33 in which there are disposed the parts forming the slide ring packing. The upper part of housing 28 contains the agitator drive. The housing 28 is closed on the top by a cover plate 34. To cover plate 34 there is secured, on the one hand, a tubular casing 23 (FIG. 1) and, on the other hand, by means of an intermediate plate 35, an electric driving motor I of the agitator (FIG. 2).

To the tapered portion 32 of the stirring shaft 10 there is threadedly secured a tie rod 9 having at its opposite end a square driving head 36. The tie rod 9 extends inside a hollow drive shaft 8 which forms the upward continuation of the stir ring shaft 10 and which is clamped to the tapered portion 32 by means of nuts 21 threadedly held on the upper terminus of the tie rod 9 adjacent the driving head 36.

The tubular casing 23 threadedly engages an axially inwardly'extending, externally threaded sleeve 22 having an upper flange 37 which abuts against a countersunk shoulder 38 of the tubular casing 23.

The drive shaft 8 is coaxially and 'spacedly surrounded by sleeve 22 and is supported therein by a bearing [2 (preferably a roller bearing) which is clampedagainst an inside shoulder 39 of the sleeve 22 by a head 40. Said head is affixed to the upper end of the sleeve 22 and is provided with an axial opening to allow therethrough a free passage of hollow shaft 8. Further, to the head 40 there is threadedly secured a cap 26 enclosing the upper terminus of the tie rod 9. The portion of the head 40 surrounded by the cap 26 and disposed above the thread therefor, is formed as a hexagonal driving head 25.

In the wall of the tubular casing 23 there is provided a window 41 which is closed by a cover 24 made, for example, of Plexiglas.

The flange 37 of the sleeve 22 is secured against accidental rotation with respect to the tubular casing 23 during the operation of the agitator, by a countersunk locking screw 2?.

Referring now to FIG. 2, the stub shaft 42 of motor I extends into a blind bore of an enlarged end portion of a shaft 3 and engages the wall of said bore by means of a rivet and spring connection with the interposition of an elastic sleeve 2. The shaft 3 is held by bearings 43 and M in the cover plate 34 and in an intermediate wall 45 of the housing 28, respectively. To shaft 3 there is keyed a pinion 4 which meshes with a gear 49 keyed to a shaft 48 which, in turn, is held in the cover plate 34 and in the intermediate wall 45 by means of bearings 50 and 51, respectively. The pinion 4 and the gear 49 may be mounted on their respective shafts 3 and 48 through an opening 47 of housing 28 normally closed by cover 46. On shaft 48 there is mounted a pinion 5 which is thus driven by motor I through the shaft 3 and the connecting gear pair 4, 49. The pinion 5 meshes with the driving spur gear 6, the hub of which is held in the closure plate 34 and in the intermediate wall 45 by means of bearings 52 and 53, respectively (FIG. I).

The spur gear 6 is connected through an elastic toothed driving disc 7, preferably made of synthetic material, with the hollow drive shaft 8 in a manner now to be described with reference to FIG. It.

To the hollow drive shaft 8 there is keyed a sleeve 54 having an integral flange 55. Between a disc 56 fitted over the end of sleeve 54 and the flange 55 there is clamped, for example, by means of screws, the peripherally toothed driving disc 7 meshing with the internal teeth 57 of the spur gear 6 and thus forming a gear clutch. In the vicinity of said clutch the hollow drive shaft 8 is held in a radial bearing 11 which, in turn, rests on an internal radial shoulder 58 of a bearing bushing 20. By virtue of this arrangement, parts 7, 54, 55 and 56 which may be axially removed from the housing 28 with the drive shaft seal as will be described hereinafter, provide an advantageous means for transmitting the stirring torque to the drive shaft 8. Axially below the bearing 11 there are positioned on the hollow drive shaft 8 the working parts of the slide ring packing by means of additional seals hermetically closing the chamber 33 in both axial directions to retain therein a packing fluid under pressure. Said working parts are formed of an upper and a lower base ring 13 and two carbon slide rings 14 arranged in axial succession between the two base rings 13.

The base rings 13 and the carbon slide rings 14 are held inside a slotted spacer ring 15 by means of snap rings 59 disposed in two axially spaced internal grooves of ring 15.

Within the chamber 33 containing the components of the slide ring packing, there is disposed a helical heat exchanger conduit 16 continuously cooling the sealing fluid (such as nitrobenzol, oil, or the like) filling the chamber 33. The conduit 16 carries a coolant, preferably water, which is introduced through the inlet 30 and taken out through the outlet 31. For improving the seal between the lower end of the hollow drive shaft 8 and the base plate 27, there is provided, between these two parts, a labyrinth seal below which, in the base plate 27, there is disposed a collecting pan 17 for the leaking fluid. The accumulated fluid may be drained, when necessary, through a channel 60 formed in the base plate 27. The outlet of channel 60 is normally closed by a plug 18.

When the slide ring packing, that is, the base rings 13 and the carbon slide rings 14 are to bereplaced, first the cap 26 is removed and the countersunk locking screw 29, as well as the nuts 21 on the upper end of tie rod 9, are loosened. Thereafter, the tie rod 9 is unscrewed from the tapered portion 32 of the stirring shaft by means of a wrench engaging the square driving head 36 of the tie rod 9. Thus, the hollow drive shaft 8 is disconnected from the stirring shaft 10. ln a known suitable manner care is taken to prevent the stirring shaft 10 from dropping into the vessel with the agitator parts secured thereto. Thus, for example, a rim (not shown) may be provided about the stirring shaft 10 to engage, after a slight downward motion of the stirring shaft, an abutment (also not shown) from which the stim'ng shaft 10 is then suspended together with the agitator parts. By means of a wrench inserted on the hexagonal driving head 25, the sleeve 22 is upwardly unscrewed from the tubular casing 23, carrying with it, by virtue of bearing 12, the hollow shaft 8 and thus all parts which the hollow shaft 8 carries. at its lower end. The hollow drive shaft 8 does not rotate during this operation since only the outer ring of the bearing 12 is rotated together with the sleeve 22. As the hollow drive shaft 8 moves upwardly, it carries with it, by virtue of the sleeve 54, the toothed disc 7, the teeth of which slide out of engagement with the in'temal teeth 57 of the spur gear 6. With the bearing 11 disposed on the hollow drive shaft 8, the bearing bushing 20 is also carried upwardly through the housing 28 and so are the base rings 13 and carbon rings 14 (held together by the spacer ring until they eventually pass through the cover plate 34 of the gear housing 28 and register with the window 41 of the tubular casing 23. Through opening 41 the working components of the slide ring packing, that is, the base rings 13 and carbon rings 14 may be manually pulled off from the lower end of the hollow drive shaft 8 in a downward direction, and then laterally removed through opening 41. It is to be noted that the lower part of hollow drive shaft 8 has no enlargements which would prevent such an operation. Thereafter, the new seal components are inserted on the hollow shaft 8 and are correctly positioned thereon. Then, all threaded parts are tightened in a reverse order. Thus, the tie rod 9 is screwed into the tapered portion 32 of the stirring shaft 10 and the hollow drive shaft 8 is tightened thereon by means of nuts 21 disposed at the upper end of the tie rod 9. The threaded sleeve 22 is then secured against rotation by the countersunk bolt 29 and finally the cap 26 is tightened on head 40.

Thus, according to the invention, the conventional coupling (usually formed as a disc or shell clutch) between the drive shaft and the stirring shaft is replaced by a coupling which does not require more radial space than shafts of usual diameter. Consequently, the decrease in axial space requirement according to the invention does not necessitate additional radial space.

l claim:

1. In a stirring apparatus of the type associated with a high pressure vessel and having (A) a gear housing disposed externally of said vessel, (B) a gear drive disposed in said housing,

and (C) a stirring shaft driven by power means through said gear drive and extending from said gear housing into said vessel, the improvement comprising:

A. a drive shaft rotatably and axially displaceably held in axial alignment with said stirring shaft;

B. securing means for disconnectably fastening said drive shaft to said stirringshaft;

C. a stirring shaft seal disposed within said housing about and in engagement with said drive shaft in the area of its contact with said stirring shaft;

D. multipart interconnected drive gear means disposed in said gear housing and coupling said power means with said drive shaft, parts of said gear means being affixed to said drive shaft behind said shaft seal when viewed from said vessel; and l E. a casing affixed to said housing externally thereof and communicating therewith, said casing having a lateral opening; said drive shaft, after being disconnected from said stirring shaft, adapted to be axially drawn through said casing together with said stirring shaft seal and said parts of said gear means for bringing said stirring shaft seal into alignment with said lateral opening.

2. An improvement as defined in claim 1, wherein said securing means are adapted to be in engagement with said stirring shaft and with said drive shaft within the diameter of the latter.

3. An improvement as defined in claim 2, wherein said stirring shaft terminates in a tapered portion in said gear housing; said drive shaft is axially hollow; said securing means includes a tie rod extending coaxially through said drive shaft and adapted to be disconnectably secured to said tapered portion.

4. An improvement as defined in claim 1, wherein said parts of said gear means affixed to said drive shaft include an externally and peripherally toothed disc coaxially affixed thereto; said drive gear means further includes a spur gear coaxially disposed with respect to said toothed disc, said spur gear has external teeth through which it is drivingly connected with said power means, said spur gear further includes internal teeth meshing with said toothed disc; said toothed disc, when said drive shaft is axially displaced, is adapted to slide out of meshing engagement with said spur gear.

5. An improvement as defined in claim 1 including a sleeve threadedly held by said casing in coaxial relation with said drive shaft; said drive shaft is suspended from said sleeve by means of a bearing and is axially displaceable away from said vessel as said sleeve is unscrewed. 

1. In a stirring apparatus of the type associated with a high pressure vessel and having (A) a gear housing disposed externally of said vessel, (B) a gear drive disposed in said housing, and (C) a stirring shaft driven by power means through said gear drive and extending from said gear housing into said vessel, the improvement comprising: A. a drive shaft rotatably and axially displaceably held in axial alignment with said stirring shaft; B. securing means for disconnectably fastening said drive shaft to said stirring shaft; C. a stirring shaft seal disposed within said housing about and in engagement with said drive shaft in the area of its contact with said stirring shaft; D. multipart interconnected drive gear means disposed in said gear housing and coupling said power means with said drive shaft, parts of said gear means being affixed to said drive shaft behind said shaft seal when viewed from said vessel; and E. a casing affixed to said housing externally thereof and communicating therewith, said casing having a lateral opening; said drive shaft, after being disconnected from said stirring shaft, adapted to be axially drawn through said casing together with said stirring shaft seal and said parts of said gear means for bringing said stirring shaft seal into alignment with said lateral opening.
 2. An improvement as defined in claim 1, wherein said securing means are adapted to be in engagement with said stirring shaft and with said drive shaft within the diameter of the latter.
 2. An improvement as defined in claim 1, wherein said securing means are adapted to be in engagement with said stirring shaft and with said drive shaft within the diameter of the latter.
 3. An improvement as defined in claim 2, wherein said stirring shaft terminates in a tapered portion in said gear housing; said drive shaft is axially hollow; said securing means iNcludes a tie rod extending coaxially through said drive shaft and adapted to be disconnectably secured to said tapered portion.
 4. An improvement as defined in claim 1, wherein said parts of said gear means affixed to said drive shaft include an externally and peripherally toothed disc coaxially affixed thereto; said drive gear means further includes a spur gear coaxially disposed with respect to said toothed disc, said spur gear has external teeth through which it is drivingly connected with said power means, said spur gear further includes internal teeth meshing with said toothed disc; said toothed disc, when said drive shaft is axially displaced, is adapted to slide out of meshing engagement with said spur gear.
 5. An improvement as defined in claim 1 including a sleeve threadedly held by said casing in coaxial relation with said drive shaft; said drive shaft is suspended from said sleeve by means of a bearing and is axially displaceable away from said vessel as said sleeve is unscrewed. 